UPDATE: The boycott worked, or at least appears to have worked. GoDaddy has reversed its public position on SOPA. See more at the bottom.

The great battle for the open Internet continues today, with opponents of the Stop Online Piracy Act (SOPA) and the Protect IP Act (PIPA) launching a boycott of domain name registrar GoDaddy, which has written the House of Representatives to express its strong support of the controversial legislation.

While Silicon Valley firms like Google, Facebook and Twitter overwhelmingly oppose SOPA on the grounds that it will usher in unprecedented censorship online, suffocate innovation, and endanger the domain name system (DNS) upon which the Internet is built, GoDaddy brushes aside all these arguments, and claims that the bill is needed to “identify and disable all types of illegal activity on the Internet.”

In addition to claiming that SOPA “[is] not going to break the Internet” by tampering with the DNS — something dozens of technical experts say is a serious risk — GoDaddy also tells the House that SOPA “cannot reasonably be equated with censorship.”

“This bill promotes action pursuant to preexisting criminal and civil laws,” continues GoDaddy in its filing with the House. “Not only is there no First Amendment concern, but the notion that we should turn a blind eye to criminal conduct because other countries may take oppressive steps in response is an affront to the very fabric of this nation – that we abide by a set rule of laws, regardless of what actions other countries choose to take or not take.”

This goes firmly against the Stanford Law Review’s take on SOPA, which is that it will, in fact, “break the Internet,” and violate the Constitution in the process.

“The Supreme Court has made it abundantly clear that governmental action suppressing speech, if taken prior to an adversary proceeding and subsequent judicial determination that the speech in question is unlawful, is a presumptively unconstitutional ‘prior restraint,’ writes the Stanford Law Review. “In other words, it is the ‘most serious and the least tolerable infringement on First Amendment rights,’ permissible only in the narrowest range of circumstances. The Constitution requires a court ‘to make a final determination’ that the material in question is unlawful ‘after an adversary hearing before the material is completely removed from circulation.’ The procedures outlined in both bills fail this fundamental constitutional test.”

Regardless of whether GoDaddy is right or wrong about the impact of SOPA, it remains incomprehensible as to why a company that is likely in violation of the bill would support Congress voting it into law.

As TechDirt’s Mike Masnik, who has covered SOPA exhaustively, notes, GoDaddy would fall under the SOPA definition of a “site dedicated to the theft of US property,” since it offers “goods or services in a manner that engages in, enables, or facilitates… the sale, distribution, or promotion of goods, services, or materials bearing a counterfeit mark.”

In other words: GoDaddy is pushing for legislation that, as written, could kill its business.

Still, the company is standing by its support for SOPA, and reposted its letter to the House on its website, after a flood of calls and emails poured in from anti-SOPA activists.

With an untold number of customers fleeing from GoDaddy, competing registrars have swooped in to pick up the slack. Many of them have begun offering promotional codes to draw in disgruntled customers. They include:

• Name.com: Use code “NODADDY” for 10 percent off transfer-in domains, and 40 percent off hosting. • HostGator.com: Use code “NOSOPA” for 50 percent off the first month of hosting.• NameCheap.com: Use “BYEBYEGD” or “SOPASucks” or “XMASJOY” for a discount.

Of course, GoDaddy is far from the only company that supports SOPA. Check out our list of hundreds of companies that either explicitly support SOPA, or have written Congress in support of similar legislation. To see who has come out against SOPA — a much longer list — click here.

UPDATE 1: GoDaddy Stands firm: The domain registrar has issued a statement to Ars Technica, stating that, “Go Daddy has received some emails that appear to stem from the boycott prompt, but we have not seen any impact to our business. We understand there are many differing opinions on the SOPA regulations.”

UPDATE 2: NoDaddy Day: Comments in the original Reddit thread indicate that December 29 has been declared ‘move your domain’ day. If the momentum holds strong, that means GoDaddy may yet feel the repercussions.

UPDATE 3:StackOverflow has confirmed that it will move its domains from GoDaddy due to its SOPA support, as has the entire Cheezburger Network, reports TechCrunch — all 1,000 domains, which include I Can Has Cheezburger, Know Your Meme, Fail Blog, the list goes on — unless the registrar reverses its position on SOPA. Cheezburger’s move follows Silicon Valley investor and Y Combinator founder Paul Graham’s declaration that any company that backs SOPA will not be invited to the Y Combinator Demo Day, a twice-a-year presentation to investors of the newest batch of graduating Y Combinator startups.

Update 4: GoDaddy caves on SOPA support to avoid boycott: “Fighting online piracy is of the utmost importance, which is why Go Daddy has been working to help craft revisions to this legislation – but we can clearly do better,” said the company’s CEO, Warren Adelman. “It’s very important that all Internet stakeholders work together on this. Getting it right is worth the wait. Go Daddy will support it when and if the Internet community supports it.”

Obviously, this could all be — and likely is — a PR stunt. That is to say, GoDaddy is trying to stop hemorrhaging money by flipping its public opinion on SOPA, but continues with a wink-wink, nudge-nudge towards Washington. Needless to say, the boycott is not yet over.